SEIGA Technique for Multiple Access Interference Computation in DS-CDMA Systems

Abstract

In literature, the performance of Direct Sequence Code Division Multiple Access (DS-CDMA) systems over multipath fading channels are evaluated by using Standard Gaussian Approximation (SGA) and Simplified Expression of Improved Gaussian Approximation (SEIGA). Especially, time-limited DS-CDMA chip waveforms are employed in the analysis by using SEIGA. In this work, the performance analysis of DS-CDMA signals having time-limited and band-limited (used in third generation communication) chip waveforms are conducted over multi-path Rayleigh fading channels by utilizing SEIGA method. The effects of classical time-limited chip waveforms and band-limited square root raised cosine (SRRC) on the Bit Error Rate (BER) performance are compared. The obtained numerical results show that time-limited raised cosine gives the best performance, whereas band-limited SRRC gives the worst in terms of the BER over Rayleigh fading channels.